We present a novel concept for a highly sensitive, medium spectral resolution optical through near-IR spectrograph. KIDSpec, the Kinetic Inductance Detector Spectrograph, uses the intrinsic energy resolving capability of an array of optical/IR-sensitive MKIDs to distinguish multiple orders from a low line-density (echelle) grating. MKID arrays have a wide bandpass (0.1-2.5um) and good quantum efficiency, making them strong candidates for replacing CCDs in many astronomical instruments. By acting as an ‘order resolver’, the MKID array replaces the cross-disperser in an echelle spectrograph. This greatly simplifies the optical layout of the spectrograph and enables longer slits than are possible with cross-dispersed instruments. KIDSpec would have similar capabilities to ESO’s X-shooter instrument. It would provide an R=4000-10,000 spectrum covering the entire optical and near-IR spectral range. In addition to a ‘long-slit’ mode, the IFU would provide a small (~50 spaxel) field-of-view for spatially resolved sources. In addition, the photon-counting operation of MKIDs and their photon-energy resolving ability enable a read-noise free spectrum with perfect cosmic ray removal. The spectral resolution would be sufficient to remove the bright night-sky lines without the additional pixel noise, making the instrument more sensitive than an equivalent semiconductor-based instrument. KIDSpec would enhance many existing high-profile science cases, including transient (GRB, SNe, etc.) follow-up, redshift determination of faint objects and transit spectroscopy of exoplanets. In addition it will enable unique science cases, such as dynamical mass estimates of the compact objects in ultra-compact binaries.

Date Published: 8 July 2014
PDF: 8 pages
Proc. SPIE 9147, Ground-based and Airborne Instrumentation for Astronomy V, 91470G (8 July 2014); doi: 10.1117/12.2056297

Published in SPIE Proceedings Vol. 9147:
Ground-based and Airborne Instrumentation for Astronomy V
Suzanne K. Ramsay; Ian S. McLean; Hideki Takami, Editor(s)